diff --git a/plugins/tasklist/drivers/database/tasklist_database_driver.php b/plugins/tasklist/drivers/database/tasklist_database_driver.php
--- a/plugins/tasklist/drivers/database/tasklist_database_driver.php
+++ b/plugins/tasklist/drivers/database/tasklist_database_driver.php
@@ -332,6 +332,10 @@
             $sql_add .= ' AND changed >= ' . $this->rc->db->quote(date('Y-m-d H:i:s', $filter['since']));
         }
 
+        if ($filter['uid']) {
+            $sql_add .= ' AND `uid` IN (' . implode(',', array_map(array($this->rc->db, 'quote'), $filter['uid'])) . ')');
+        }
+
         $tasks = array();
         if (!empty($list_ids)) {
             $result = $this->rc->db->query(sprintf(
diff --git a/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php b/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php
--- a/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php
+++ b/plugins/tasklist/drivers/kolab/tasklist_kolab_driver.php
@@ -550,6 +550,7 @@
      *  - from:  Date range start as string (Y-m-d)
      *  - to:    Date range end as string (Y-m-d)
      *  - search: Search query string
+     *  - uid:   Task UIDs
      * @param array List of lists to get tasks from
      * @return array List of tasks records matchin the criteria
      */
@@ -585,6 +586,10 @@
             $query[] = array('changed', '>=', $filter['since']);
         }
 
+        if ($filter['uid']) {
+            $query[] = array('uid', '=', (array) $filter['uid']);
+        }
+
         foreach ($lists as $list_id) {
             if (!$folder = $this->get_folder($list_id)) {
                 continue;
diff --git a/plugins/tasklist/localization/en_US.inc b/plugins/tasklist/localization/en_US.inc
--- a/plugins/tasklist/localization/en_US.inc
+++ b/plugins/tasklist/localization/en_US.inc
@@ -13,6 +13,10 @@
 $labels['lists'] = 'Tasklists';
 $labels['list'] = 'Tasklist';
 $labels['tags'] = 'Tags';
+$labels['export'] = 'Export';
+$labels['exporttitle'] = 'Export to iCalendar';
+$labels['exportattachments'] = 'With attachments';
+$labels['currentview'] = 'current view';
 $labels['tasklistsubscribe'] = 'List permanently';
 $labels['listsearchresults'] = 'Available Tasklists';
 $labels['findlists'] = 'Find tasklists...';
diff --git a/plugins/tasklist/skins/larry/buttons.png b/plugins/tasklist/skins/larry/buttons.png
deleted file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
GIT binary patch
literal 0
Hc$@<O00001

literal 0
Hc$@<O00001

diff --git a/plugins/tasklist/skins/larry/images/buttons.png b/plugins/tasklist/skins/larry/images/buttons.png
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
GIT binary patch
literal 0
Hc$@<O00001

literal 0
Hc$@<O00001

diff --git a/plugins/tasklist/skins/larry/sprites.png b/plugins/tasklist/skins/larry/images/sprites.png
rename from plugins/tasklist/skins/larry/sprites.png
rename to plugins/tasklist/skins/larry/images/sprites.png
diff --git a/plugins/tasklist/skins/larry/tasklist.css b/plugins/tasklist/skins/larry/tasklist.css
--- a/plugins/tasklist/skins/larry/tasklist.css
+++ b/plugins/tasklist/skins/larry/tasklist.css
@@ -11,7 +11,7 @@
  */
 
 #taskbar a.button-tasklist span.button-inner {
-	background-image: url(buttons.png);
+	background-image: url(images/buttons.png);
 	background-position: 0 0;
 }
 
@@ -22,10 +22,22 @@
 
 ul.toolbarmenu li span.icon.taskadd,
 #attachmentmenu li a.tasklistlink span.icon.taskadd {
-	background-image: url(buttons.png);
+	background-image: url(images/buttons.png);
 	background-position: -4px -90px;
 }
 
+#taskstoolbar a.button.export {
+	background-image: url(images/buttons.png);
+	background-position: center -179px;
+	min-width: 50px;
+	max-width: 70px;
+}
+
+#taskstoolbar a.button.import {
+	background-image: url(images/buttons.png);
+	background-position: center -139px;
+}
+
 #taskedit.uidialog,
 .tasklistview div.uidialog {
 	display: none;
@@ -296,7 +308,7 @@
 	overflow: hidden;
 	text-overflow: ellipsis;
 	white-space: nowrap;
-	background: url(sprites.png) right 20px no-repeat;
+	background: url(images/sprites.png) right 20px no-repeat;
 }
 
 .quickview-active #tasklistsbox .treelist li input,
@@ -341,7 +353,7 @@
 	height: 16px;
 	padding: 0;
 	margin-right: 4px;
-	background: url(sprites.png) -200px 0 no-repeat;
+	background: url(images/sprites.png) -200px 0 no-repeat;
 	overflow: hidden;
 	text-indent: -5000px;
 	cursor: pointer;
@@ -461,7 +473,7 @@
 }
 
 #taskstoolbar a.button.newtask {
-	background-image: url(buttons.png);
+	background-image: url(images/buttons.png);
 	background-position: center -53px;
 }
 
@@ -547,7 +559,7 @@
 
 .buttonbar-right a.iconbutton {
 	padding: 0;
-	background-image: url(sprites.png);
+	background-image: url(images/sprites.png);
 	background-position: 0 -238px;
 }
 
@@ -599,7 +611,7 @@
 	
 	width: 14px;
 	height: 14px;
-	background: url(sprites.png) -2px -80px no-repeat;
+	background: url(images/sprites.png) -2px -80px no-repeat;
 	text-indent: -1000px;
 	overflow: hidden;
 }
@@ -648,7 +660,7 @@
 	display: inline-block;
 	width: 16px;
 	height: 16px;
-	background: url(sprites.png) 1000px -3px no-repeat;
+	background: url(images/sprites.png) 1000px -3px no-repeat;
 	margin: -3px 1em 0 0;
 	vertical-align: middle;
 	cursor: pointer;
@@ -730,7 +742,7 @@
 	right: 6px;
 	width: 18px;
 	height: 18px;
-	background: url(sprites.png) 1000px -80px no-repeat;
+	background: url(images/sprites.png) 1000px -80px no-repeat;
 	text-indent: -5000px;
 	overflow: hidden;
 	cursor: pointer;
@@ -772,7 +784,7 @@
 ul.toolbarmenu li span.collapse,
 ul.toolbarmenu li span.history,
 ul.toolbarmenu.iconized .selected span.icon {
-	background-image: url(sprites.png);
+	background-image: url(images/sprites.png);
 }
 
 ul.toolbarmenu li span.add {
@@ -1162,7 +1174,7 @@
 
 #taskedit-links .attachmentslist li.message.eml,
 #task-links .attachmentslist li.message.eml {
-	background-image: url(sprites.png);
+	background-image: url(images/sprites.png);
 	background-position: -2px -388px;
 }
 
@@ -1411,7 +1423,7 @@
 	left: 8px;
 	width: 18px;
 	height: 18px;
-	background: url(buttons.png) -6px -115px no-repeat;
+	background: url(images/buttons.png) -6px -115px no-repeat;
 }
 
 div.messagetasklinks ul.tasklist {
diff --git a/plugins/tasklist/skins/larry/templates/mainview.html b/plugins/tasklist/skins/larry/templates/mainview.html
--- a/plugins/tasklist/skins/larry/templates/mainview.html
+++ b/plugins/tasklist/skins/larry/templates/mainview.html
@@ -17,6 +17,7 @@
 		<div id="taskstoolbar" class="toolbar" role="toolbar" aria-labelledby="aria-label-toolbar">
 			<roundcube:button command="newtask" type="link" class="button newtask disabled" classAct="button newtask" classSel="button newtask pressed" label="tasklist.newtask" title="tasklist.newtask" />
 			<roundcube:button command="print" type="link" class="button print disabled" classAct="button print" classSel="button print pressed" label="print" title="tasklist.printtitle" />
+			<roundcube:button command="export" type="link" class="button export disabled" classAct="button export" classSel="button export pressed" label="tasklist.export" title="tasklist.exporttitle" />
 			<roundcube:container name="toolbar" id="taskstoolbar" />
 		</div>
 
@@ -320,6 +321,10 @@
 	<roundcube:container name="tasklistform" id="tasklistform" />
 </div>
 
+<div id="tasksexport" class="uidialog">
+	<roundcube:object name="plugin.tasks_export_form" id="tasks-export-form" />
+</div>
+
 <script type="text/javascript">
 
 // UI startup
diff --git a/plugins/tasklist/tasklist.js b/plugins/tasklist/tasklist.js
--- a/plugins/tasklist/tasklist.js
+++ b/plugins/tasklist/tasklist.js
@@ -820,6 +820,92 @@
         loadstate.lists = active_lists();
     }
 
+    // open a tasks export dialog
+    this.export_tasks = function()
+    {
+      // close show dialog first
+      var $dialog = $("#tasksexport"),
+        form = rcmail.gui_objects.exportform,
+        buttons = {};
+
+      if (!form)
+        return;
+
+      if ($dialog.is(':ui-dialog'))
+        $dialog.dialog('close');
+
+      $("#task-export-list").val('');
+
+      buttons[rcmail.gettext('export', 'tasklist')] = function() {
+        var source = $('#task-export-list option:selected').val();
+
+        // "current view" export, use hidden form to POST task IDs
+        if (source === '') {
+          var cache = {}, tasks = [], inputs = [],
+            postform = $('#tasks-export-form-post');
+
+          $.each(listindex || [], function() {
+            var rec = listdata[this];
+            if (match_filter(rec, cache)) {
+              tasks.push(rec.id);
+            }
+          });
+
+          // copy form inputs, there may be controls added by other plugins
+          $('#tasksexport select, #tasksexport input').each(function() {
+            if (this.type != 'checkbox' || this.checked)
+              inputs.push($('<input>').attr({type: 'hidden', name: this.name, value: this.value}));
+          });
+
+          inputs.push($('<input>').attr({type: 'hidden', name: '_token', value: rcmail.env.request_token}));
+          inputs.push($('<input>').attr({type: 'hidden', name: 'id', value: tasks.join(',')}));
+
+          if (!postform.length)
+            postform = $('<form>')
+              .attr({style: 'display: none', method: 'POST', action: '?_task=tasks&_action=export'})
+              .appendTo('body');
+
+          postform.html('').append(inputs).submit();
+        }
+        // otherwise we can use simple GET
+        else {
+          rcmail.goto_url('export', {source: source, attachments: attach});
+        }
+
+        $dialog.dialog("close");
+      };
+
+      buttons[rcmail.gettext('cancel', 'tasklist')] = function() {
+        $dialog.dialog("close");
+      };
+
+      // open jquery UI dialog
+      $dialog.dialog({
+        modal: true,
+        resizable: false,
+        closeOnEscape: false,
+        title: rcmail.gettext('exporttitle', 'tasklist'),
+        open: function() {
+          $dialog.parent().find('.ui-dialog-buttonset .ui-button').first().addClass('mainaction');
+        },
+        close: function() {
+          $('.ui-dialog-buttonpane button', $dialog.parent()).button('enable');
+          $dialog.dialog("destroy").hide();
+        },
+        buttons: buttons,
+        width: 520
+      }).show();
+    };
+/*
+    // download the selected task as iCal
+    this.task_download = function(task)
+    {
+      if (task && task.id) {
+        rcmail.goto_url('export', {source: task.list, id: task.id, attachments: 1});
+      }
+    };
+*/
+
     /**
      * Modify query parameters for refresh requests
      */
@@ -3367,6 +3453,7 @@
   rcmail.register_command('list-remove', function(){ rctasks.list_remove(rctasks.selected_list); }, false);
   rcmail.register_command('list-showurl', function(){ rctasks.list_showurl(rctasks.selected_list); }, false);
 
+  rcmail.register_command('export', function(){ rctasks.export_tasks(); }, true);
   rcmail.register_command('search', function(){ rctasks.quicksearch(); }, true);
   rcmail.register_command('reset-search', function(){ rctasks.reset_search(); }, true);
   rcmail.register_command('expand-all', function(){ rctasks.expand_collapse(true); }, true);
diff --git a/plugins/tasklist/tasklist.php b/plugins/tasklist/tasklist.php
--- a/plugins/tasklist/tasklist.php
+++ b/plugins/tasklist/tasklist.php
@@ -119,6 +119,7 @@
             $this->register_action('mail2task', array($this, 'mail_message2task'));
             $this->register_action('get-attachment', array($this, 'attachment_get'));
             $this->register_action('upload', array($this, 'attachment_upload'));
+            $this->register_action('export', array($this, 'export_tasks'));
             $this->register_action('mailimportitip', array($this, 'mail_import_itip'));
             $this->register_action('mailimportattach', array($this, 'mail_import_attachment'));
             $this->register_action('itip-status', array($this, 'task_itip_status'));
@@ -1578,6 +1579,79 @@
         return $p;
     }
 
+    /**
+     * Construct the ics file for exporting tasks to iCalendar format
+     */
+    function export_tasks()
+    {
+        $source      = rcube_utils::get_input_value('source', rcube_utils::INPUT_GPC);
+        $task_id     = rcube_utils::get_input_value('id', rcube_utils::INPUT_GPC);
+        $attachments = (bool) rcube_utils::get_input_value('attachments', rcube_utils::INPUT_GPC);
+
+        $this->load_driver();
+
+        $browser = new rcube_browser;
+        $lists   = $this->driver->get_lists();
+        $tasks   = array();
+        $filter  = array();
+
+        // get message UIDs for filter
+        if ($source && ($list = $lists[$source])) {
+            $filename = html_entity_decode($list['name']) ?: $sorce;
+            $filter   = array($source => true);
+        }
+        else if ($task_id) {
+            $filename = 'tasks';
+            foreach (explode(',', $task_id) as $id) {
+                list($list_id, $task_id) = explode(':', $id, 2);
+                if ($list_id && $task_id) {
+                    $filter[$list_id][] = $task_id;
+                }
+            }
+        }
+
+        // Get tasks
+        foreach ($filter as $list_id => $uids) {
+            $_filter = is_array($uids) ? array('uid' => $uids) : null;
+            $_tasks  = $this->driver->list_tasks($_filter, $list_id);
+            if (!empty($_tasks)) {
+                $tasks = array_merge($tasks, $_tasks);
+            }
+        }
+
+        // Set file name
+        if ($source && count($tasks) == 1) {
+            $filename = $tasks[0]['title'] ?: 'task';
+        }
+        $filename .= '.ics';
+        $filename = $browser->ie ? rawurlencode($filename) : addcslashes($filename, '"');
+
+        $tasks = array_map(array($this, 'to_libcal'), $tasks);
+
+        // Give plugins a possibility to implement other output formats or modify the result
+        $plugin = $this->rc->plugins->exec_hook('tasks_export', array(
+                'result'      => $tasks,
+                'attachments' => $attachments,
+                'filename'    => $filename,
+                'plugin'      => $this,
+        ));
+
+        if ($plugin['abort']) {
+            exit;
+        }
+
+        $this->rc->output->nocacheing_headers();
+
+        // don't kill the connection if download takes more than 30 sec.
+        @set_time_limit(0);
+        header("Content-Type: text/calendar");
+        header("Content-Disposition: inline; filename=\"". $plugin['filename'] ."\"");
+
+        $this->get_ical()->export($plugin['tasks'], '', true,
+            $plugins['attachments'] ? array($this->driver, 'get_attachment_body') : null);
+        exit;
+    }
+
 
     /******* Attachment handling  *******/
 
diff --git a/plugins/tasklist/tasklist_ui.php b/plugins/tasklist/tasklist_ui.php
--- a/plugins/tasklist/tasklist_ui.php
+++ b/plugins/tasklist/tasklist_ui.php
@@ -161,6 +161,7 @@
         $this->plugin->register_handler('plugin.edit_attendees_notify', array($this, 'edit_attendees_notify'));
         $this->plugin->register_handler('plugin.task_rsvp_buttons', array($this->plugin->itip, 'itip_rsvp_buttons'));
         $this->plugin->register_handler('plugin.object_changelog_table', array('libkolab', 'object_changelog_table'));
+        $this->plugin->register_handler('plugin.tasks_export_form', array($this, 'tasks_export_form'));
 
         jqueryui::tagedit();
 
@@ -310,11 +311,18 @@
      */
     function tasklist_select($attrib = array())
     {
-        $attrib['name']       = 'list';
+        if (empty($attrib['name'])) {
+            $attrib['name'] = 'list';
+        }
+
         $attrib['is_escaped'] = true;
         $select = new html_select($attrib);
         $default = null;
 
+        foreach ((array) $attrib['extra'] as $id => $name) {
+            $select->add($name, $id);
+        }
+
         foreach ((array)$this->plugin->driver->get_lists() as $id => $prop) {
             if ($prop['editable'] || strpos($prop['rights'], 'i') !== false) {
                 $select->add($prop['name'], $id);
@@ -526,6 +534,38 @@
     }
 
     /**
+     * Form to select options for exporting tasks
+     */
+    function tasks_export_form($attrib = array())
+    {
+        if (!$attrib['id']) {
+            $attrib['id'] = 'rcmTaskExportForm';
+        }
+
+        $html .= html::div('form-section',
+            html::label('task-export-list', $this->plugin->gettext('list')) .
+                $this->tasklist_select(array(
+                        'name'  => 'source',
+                        'id'    => 'task-export-list',
+                        'extra' => array('' => '- ' . $this->plugin->gettext('currentview') . ' -'),
+                ))
+        );
+
+        $checkbox = new html_checkbox(array('name' => 'attachments', 'id' => 'task-export-attachments', 'value' => 1));
+        $html .= html::div('form-section',
+            html::label('task-export-attachments', $this->plugin->gettext('exportattachments')) .
+                $checkbox->show(1)
+        );
+
+        $this->register_gui_object('exportform', $attrib['id']);
+
+        return html::tag('form', array('action' => $this->rc->url(array('task' => 'tasklist', 'action' => 'export')),
+            'method' => "post", 'id' => $attrib['id']),
+            $html
+        );
+    }
+
+    /**
      * Wrapper for rcube_output_html::add_gui_object()
      */
     function register_gui_object($name, $id)
diff --git a/source/tasklist_buttons.psd b/source/tasklist_buttons.psd
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
GIT binary patch
literal 0
Hc$@<O00001

literal 0
Hc$@<O00001

diff --git a/source/tasklist_sprites.psd b/source/tasklist_sprites.psd
new file mode 100644
index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
GIT binary patch
literal 0
Hc$@<O00001

literal 0
Hc$@<O00001